1. Field of the Invention
The present invention relates to a plasma display device, and more particularly, to a plasma display device having an improved address electrode structure.
2. Description of the Related Art
In a plasma display device, a glow discharge occurs by applying a predetermined voltage between two electrodes and a fluorescent layer is excited by ultraviolet light generated by the glow discharge, thereby forming a picture image.
Plasma display devices are divided into direct current (DC) plasma display devices and alternating current (AC) plasma display devices according to their operating principles. Also, depending on the electrode structure, the plasma display device has two or three electrodes for discharge. In the DC plasma display device, an auxiliary anode is additively installed for inducing an auxiliary discharge. In the AC plasma display device, an address electrode is introduced for separately providing a selective discharge and a sustaining discharge to enhance addressing speed.
Also, the electrode structure of the AC plasma display device can be classified into an opposing electrode structure and a surface-discharge type electrode structure, according to the arrangement of discharge-inducing electrodes. In the former case, two discharge-inducing sustaining electrodes are disposed on a front substrate and a rear substrate, respectively, so that a discharge takes place in a direction perpendicular to the panel. In the latter case, two sustaining electrodes are disposed on a substrate so that a discharge takes place along the substrate.
FIG. 1 shows an example of a surface-discharge plasma display device. Referring to FIG. 1, a dielectric layer 13 having an address electrode 12 embedded therein is formed on the upper surface of a lower substrate 11, and a partition 14 having a predetermined pattern for defining a discharge space is formed on the upper surface of the dielectric layer 13. An upper substrate 15 is located above the partition 14 and a common electrode 16 and a scanning electrode 17, each having a predetermined pattern, are formed on the lower surface of the upper substrate 15 perpendicular to the address electrode 12. A bus electrode (not shown) for reducing electrode resistance may be formed in the common electrode 16 and the scanning electrode 17.
A dielectric layer 18 having the common electrode 16 and the scanning electrode 17 embedded therein is formed on the lower surface of the upper substrate 15, and a protective layer 19 made of MgO coats on the lower surface of the dielectric layer 18.
Also, a fluorescent layer 10 is formed on the upper surface of the dielectric layer 13 between neighboring partitions 14. A discharge gas fills the discharge space.
In operation the conventional plasma display device having the above structure, when a voltage is applied to the address electrode 12 and the common electrode 16, wall charges are accumulated by a trigger discharge. In such a state, a glow discharge occurs between the common electrode 16 and the scanning electrode 17, thereby producing light. Then, the fluorescent layer 10 is excited by ultraviolet light, thereby forming a picture image.
In the above-described plasma display device, since the address electrode 12 is formed in strips perpendicular to the scanning electrodes 17, the time necessary for addressing the address electrode 12 depends on the number of the scanning electrodes 17. Thus, the fewer the scanning electrodes there are, the longer the sustaining time is necessary.
An example of an address electrode which can reduce the sustaining time considering the above problem is shown in FIG. 2.
As shown in FIG. 2, an address electrode 12' disposed between neighboring partitions 14' and covered by a dielectric layer 13' is divided into two parts at the center of an effective screen of a plasma display device. However, even in the case of the address electrode being thus constructed, if there are many scanning electrodes, sufficient brightness cannot be attained.